In vitro effect of hydrocortisone on the attachment and ingestion phases of immunoglobulin G- and complement component 3b-mediated phagocytosis by human neutrophils

Phagocyte function of peripheral neutrophil granulocytes and monocytes in endometriosis before and after surgery

INTRODUCTION

Endometriosis is a chronic systemic disease, which influence negatively the quality of life of affected women and responsible for infertility and chronic pelvic pain. Pathophysiology of the disease is still enigmatic, but insufficient immune surveillance may play a role in it. Peripheral natural immune cell function is rarely examined. The aim of the study was to examine phagocyte function of peripheral neutrophil granulocytes and monocytes, whether this phagocytic activity is affected by the presence or removal of endometriotic lesions in women with endometriosis.

MATERIAL AND METHODS

Twenty-six preoperative, 13 postoperative samples from women with endometriosis, 23 samples from healthy women, 14 pre- and postoperative samples from the surgical control group were enrolled. Cells were isolated from peripheral blood samples, marked and evaluated for the phagocytosis index with immunofluorescent microscope after phagocyting the zymosane molecules.

RESULTS

Phagocyte function of monocytes and neutrophil granulocytes decreased significantly women with endometriosis before surgery compared to healthy controls. However, 7 days after surgery the postoperative values showed significant improvement compared to the preoperative results of women with endometriosis. This increment reached the values of the healthy women. In the surgical control group no difference was detected between the pre- and postoperative outcomes.

DISCUSSION

Decreased phagocyte function of the examined cells, which can be the result of the circulating immunosuppressive factors, may play a role in the deficient clearance of ectopic endometrial tissue. Based on the postoperative results, these immunosuppressive factors may be reduced or eliminated 7 days after surgery in women with endometriosis.

Metabolites of Aliphatic Alcohols Detected in Alcoholic Beverages Inhibit Phagocytosis

AIMS

The aim of our study was to measure granulocyte and monocyte phagocytosis following treatment of cells with some metabolites of aliphatic alcohols alone and in combination with acetaldehyde.

METHODS

The cells were separated from human peripheral blood prior to determination of phagocytosis of opsonized zymosan particles by granulocytes and monocytes treated individually with metabolites of aliphatic alcohols including formaldehyde, 1-propanal, acetone, 1-butanal, and 2-butanone and in combination with acetaldehyde.

RESULTS

The findings revealed that metabolites of aliphatic alcohols inhibited phagocytosis by granulocytes and monocytes in a concentration-dependent manner and when combined with acetaldehyde, they caused a further decrease in phagocytic activity.

CONCLUSION

Due to their additive effects, it is possible that, in combination with acetaldehyde, metabolites of aliphatic alcohols may inhibit phagocytosis at physiologically realistic concentrations in episodic heavy drinkers, thereby contributing to their increased susceptibility to infectious diseases.

Aliphatic alcohols in spirits inhibit phagocytosis by human monocytes

A large volume of alcoholic beverages containing aliphatic alcohols is consumed worldwide. Previous studies have confirmed the presence of ethanol-induced immunosuppression in heavy drinkers, thereby increasing susceptibility to infectious diseases. However, the aliphatic alcohols contained in alcoholic beverages might also impair immune cell function, thereby contributing to a further decrease in microbicidal activity. Previous research has shown that aliphatic alcohols inhibit phagocytosis by granulocytes but their effect on human monocytes has not been studied. This is important as they play a crucial role in engulfment and killing of pathogenic microorganisms and a decrease in their phagocytic activity could lead to impaired antimicrobial defence in heavy drinkers. The aim of this study was to measure monocyte phagocytosis following their treatment with those aliphatic alcohols detected in alcoholic beverages. Monocytes were separated from human peripheral blood and phagocytosis of opsonized zymosan particles by monocytes treated with ethanol and aliphatic alcohols individually and in combination was determined. It was shown that these alcohols could suppress the phagocytic activity of monocytes in a concentration-dependent manner and when combined with ethanol, they caused a further decrease in phagocytosis. Due to their additive effects, it is possible that they may inhibit phagocytosis in a clinically meaningful way in alcoholics and episodic heavy drinkers thereby contribute to their increased susceptibility to infectious diseases. However, further research is needed to address this question.

Effect of post-exercise protein-leucine feeding on neutrophil function, immunomodulatory plasma metabolites and cortisol during a 6-day block of intense cycling

Whey protein and leucine ingestion following exercise increases muscle protein synthesis and could influence neutrophil function during recovery from prolonged intense exercise. We examined the effects of whey protein and leucine ingestion post-exercise on neutrophil function and immunomodulators during a period of intense cycling. In a randomized double-blind crossover, 12 male cyclists ingested protein/leucine/carbohydrate/fat (LEUPRO 20/7.5/89/22 g h(-1), respectively) or isocaloric carbohydrate/fat control (CON 119/22 g h(-1)) beverages for 1-3 h post-exercise during 6 days of high-intensity training. Blood was taken pre- and post-exercise on days 1, 2, 4 and 6 for phorbol myristate acetate (PMA)-stimulated neutrophil superoxide (O2 (-)) production, immune cell counts, amino acid and lipid metabolism via metabolomics, hormones (cortisol, testosterone) and cytokines (interleukin-6, interleukin-10). During recovery on day 1, LEUPRO ingestion increased mean concentrations of plasma amino acids (glycine, arginine, glutamine, leucine) and myristic acid metabolites (acylcarnitines C14, myristoylcarnitine; and C14:1-OH, hydroxymyristoleylcarnitine) with neutrophil priming capacity, and reduced neutrophil O2 production (15-17 mmol O2 (-) cell(-1) ± 90 % confidence limits 20 mmol O2 (-) cell(-1)). On day 2, LEUPRO increased pre-exercise plasma volume (6.6 ± 3.8 %) but haematological effects were trivial. LEUPRO supplementation did not substantially alter neutrophil elastase, testosterone, or cytokine concentrations. By day 6, however, LEUPRO reduced pre-exercise cortisol 21 % (±15 %) and acylcarnitine C16 (palmitoylcarnitine) during exercise, and increased post-exercise neutrophil O2 (-) (33 ± 20 mmol O2 (-) cell(-1)), relative to control. Altered plasma amino acid and acylcarnitine concentrations with protein-leucine feeding might partly explain the acute post-exercise reduction in neutrophil function and increased exercise-stimulated neutrophil oxidative burst on day 6, which could impact neutrophil-dependent processes during recovery from intense training.

Prolonged suppression of the innate immune system in the horse following an 80 km endurance race

REASONS FOR PERFORMING STUDY

An increased susceptibility to bacterial and viral infections of the respiratory tract, which results in a loss of performance, has been reported in racehorses. Much research has focused on the influence of high-intensity exercise of a short duration on immune system function in horses, but scant attention has been given to prolonged endurance exercise as an immune modulator.

OBJECTIVES

The objective of this study was to evaluate the effect of an 80 km endurance race on the monocyte and neutrophil oxidative burst, serum cortisol, glutamine and plasma glucose concentrations in 8 endurance-trained horses (mean +/- s.d. age 9.4 +/- 2.2 years).

METHODS

Blood samples were drawn from the horses prior to and following an 80 km ride.

RESULTS

Mean time for completion of the 80 km race was 306 +/- 40 mins. Immediately post race mean serum cortisol concentration, blood monocyte and neutrophil counts were higher and blood lymphocyte counts and plasma glucose concentration were lower compared with prerace values (P < 0.05). Neutrophil and monocyte oxidative burst activity decreased following the race and had not regained prerace values after 3 days of rest (P < 0.05).

CONCLUSIONS

The present study indicates that long duration exercise in horses has a negative impact on the function of the innate immune system that lasts several days post race. Precise mechanisms instigating the fall in innate immune system function are unclear and multifactorial, but may be attributed, at least in part, to a high serum cortisol response during very prolonged exercise.

POTENTIAL CLINICAL RELEVANCE

A prolonged bout of exercise results in a long-term suppression of the innate immune system function in horses which may, in part, account for the observed increase of infectious episodes in horses during training.

Effect of low-dose prednisone in vivo on the ability of complement receptor to mediate an oxidative burst in rat neutrophils

Glucocorticoids have been used in the treatment of a variety of inflammatory processes including autoimmune diseases. However, the influence of low-dose glucocorticoids on the respiratory burst activity of neutrophils has not been studied. The aim of this work was to study the effect of treatment with low-dose prednisone on the oxidative burst of rat peripheral blood neutrophils. Wistar male rats were treated with prednisone by gavage (28, 87 or 257 microg/animal/day) for 7 or 15 days. These doses are equivalent to 10, 30 or 90 mg/adult human ( approximately 70 kg)/day, respectively. Sera from normal rats were used to opsonize zymosan (opZy). Neutrophils (1x10(5)) were stimulated by opZy and the oxidative burst of control or treated rat cells was measured by luminol-dependent chemiluminescence (CL). Prednisone did not affect the CL of rat neutrophils for either period of treatment, or any studied doses, when compared with controls. These results suggest that the low-dose prednisone has no effect on the oxidative burst mediated by complement receptors during the rat neutrophil phagocytosis of complement-opZy.

Serum antibody response to influenza vaccine in pulmonary patients receiving corticosteroids

OBJECTIVE

Despite the recommendation that patients with chronic lung diseases--many of whom receive corticosteroids--receive annual influenza vaccination, it is not known whether corticosteroids influence antibody response to influenza vaccine in this population. The purpose of this study was to assess whether patients with pulmonary conditions receiving long-term corticosteroid therapy develop an adequate antibody response.

DESIGN

We prospectively studied 39 consecutive candidates for influenza vaccination, 25 of whom were receiving corticosteroids for underlying lung diseases. Patients with immunosuppression besides corticosteroids were excluded. Serum samples were obtained prior to and 1 month after vaccination with inactivated trivalent influenza vaccine and assayed for antibodies to the three strains using a hemagglutination inhibition assay. No patients had any intercurrent illness compatible with influenza during the study period and patients receiving corticosteroids continued treatment with them during this time.

RESULTS

A fourfold rise in antibody titer at 1 month to at least one component was seen in 21 of 25 (84%) of corticosteroid-treated patients, which was similar to patients not receiving corticosteroids (11/14, 79%). There was no corticosteroid-antibody, dose-response relationship.

CONCLUSIONS

Patients with pulmonary conditions receiving corticosteroids can generate an adequate antibody response to killed influenza virus vaccine. Long-term therapy with corticosteroids should not preclude influenza vaccination in patients with chronic pulmonary diseases who are deemed vaccine candidates.

Neutrophil phagocytosis during endotoxin-induced lung injury

Depressed neutrophil (PMN) phagocytosis in patients with ARDS may contribute to the known increased incidence of pulmonary sepsis. To evaluate changes in phagocytosis, circulating PMNs from normal rats were compared to circulating and alveolar PMNs (obtained by bronchoalveolar lavage, BAL) from rats after 72 hr of endotoxin infusion (LPS-Rx)-induced acute lung injury. Since phagocytosis correlates with adherence, PMN adherence to coverslips and to a standard nylon wool column was also measured. PMN adherence to nylon wool was 65% for control, 77% for circulating LPS-Rx, and 20% for BAL PMNs. As a measure of phagocytosis the PMNs were incubated for 30 min with opsonized fluorescent (FITC) tagged yeast. Total PMN with yeast were 95.4 +/- 2.1% for control; 96.4 +/- 1.8% for circulating LPS-Rx; and 78.7 +/- 7.8% (P less than 0.05 compared to control) for BAL PMNs. Total numbers of yeast particles per 100 PMN are 270 +/- 64 for control, 300 +/- 42 for circulating LPS-Rx, and 170 +/- 45 (P less than 0.05 compared to control) for BAL PMN.

CONCLUSIONS

(1) Intraalveolar (BAL) PMNs have decreased adherence; (2) nonadherent PMNs have decreased uptake of yeast; (3) BAL PMNs, overall, have a significantly decreased uptake of yeast; (4) this depression in BAL PMN phagocytosis may partially explain the known decreased rate of bacterial clearance in injured lungs and the increased risk of pulmonary sepsis with adult respiratory distress syndrome.

Viral-bacterial synergistic interaction in respiratory disease

In the present review we have identified how viruses can alter the host's susceptibility to bacterial infections by altering both environmental conditions in the lung which favor bacterial replication as well as by suppressing the host's defense mechanisms which prevent clearance of the bacteria. In many instances, these interactions are extremely complex but similar for many viruses. If the virus can overcome the initial host defense mechanisms, which include local antibody and mucus, the virus initiates tissue damage as a result of direct replication within the epithelial cells lining the mucosal surfaces of the respiratory tract. As a result of virus infection, the host cells respond by producing a variety of mediators including various types of interferons, which can alter both virus replication and host response. Replication also produces by-products of virus infection capable of initiating an inflammatory process, which in turn, through release of other mediators, can further modify lung defense mechanisms and encourage bacterial adherence and growth. The bacterium, in turn, releases chemotactic factors which encourage infiltration of specific effector cells into the lung. These effector cells can cause tissue damage and immunopathology, which encourage rapid bacterial growth and may result in death of the animal. In order to be able to control this complicated scenario, it is important either to prevent the initial infection with viruses or to reduce the degree of immunosuppression, so that bacterial clearance can occur rapidly before microcolony formation and extensive lung damage occur. Once a large amount of bacterial replication and lung damage is present, the use of antibiotics is generally of limited value. A schematic illustration of the complexity of the various interactions and counteractions occurring during virus--bacterial synergistic interactions is presented in Fig. 1.

Corticosteroids attenuate sensitization-induced membrane changes in airway smooth muscle cells

Serum from immunized guinea pigs or highly purified IgG1 induces specific changes in electrical and contractile characteristics of airway smooth muscle (ASM) cells. In this study, the effect of hydrocortisone and prednisolone pre-treatment on the events caused by a passive in vitro sensitization of ASM cells was investigated. ASM preparations isolated from male guinea pigs were exposed to immunized serum (1:10 dilution) together with different concentrations of hydrocortisone or prednisolone administered simultaneously or 30, 120 or 240 min before addition of immunized serum. During sensitization as well as during consecutive specific antigen challenges (1 mg/ml ovalbumin), both the resting membrane potential (Em) and isometric force developed by airway smooth muscle preparations were determined. Em was determined with glass microelectrodes and isometric force was simultaneously measured with a copper-berylium strain gauge. Pretreatment with both hydrocortisone and prednisolone (in the range of 10(-8)-10(-4) M) attenuated sensitization-induced transient depolarization and steady state hyperpolarization of ASM cells and decreased the sensitization-induced development of the isometric force. Furthermore, pretreatment with either steroid significantly attenuated electrical and contractile responses to a specific antigen challenge. Inhibition of the events observed during sensitization occurred at steroid concentrations as low as 10(-8) M. We have also found that the duration of exposure of ASM cells to either of the tested steroids is critical in determining the magnitude of this inhibitory effect and seems to be more important than concentration of tested steroids.(ABSTRACT TRUNCATED AT 250 WORDS)

Human polymorphonuclear leukocytes of the bone marrow, circulation, and marginated pool: function and granule protein content

Polymorphonuclear leukocytes (PMN) demonstrate altered function during acute infections and after administration of corticosteroids. We questioned whether or not such changes are due to population shifts from functionally different compartments of the granulocyte pool. Volunteers were given epinephrine to induce demargination or hydrocortisone (HC) to promote egress of PMN from the bone marrow. PMN obtained before and after drug administration were compared for adherence, chemotaxis, luminol-enhanced chemiluminescence, and total content and release of lactoferrin (LF), myeloperoxidase (MPO), and beta-glucuronidase (beta-glu). Epinephrine induced a significant neutrophilia of mature PMN (segmented neutrophils), but there were no changes in function or granule protein content. HC induced a significant neutrophilia with segmented neutrophils and immature PMN (bands). Circulating PMN obtained 4 hr after HC administration demonstrated less adherence, increased chemiluminescence, increased MPO release, and decreased MPO content. Band neutrophils, however, were more adherent than segmented PMN and showed a similar decrease in adherence following HC in vivo. Thus alteration of PMN adherence following intravenous corticosteroids is not due to an influx of immature neutrophils. On the other hand, it is possible that MPO content and release and capacity for oxidative metabolism change as PMN mature.

Mechanisms of glucocorticoid action in pulmonary disease

This article reviews the multiple mechanisms by which glucocorticoids influence the pathophysiology of pulmonary disease. Particular emphasis is given to the influence of glucocorticoids on the release and action of mediators that promote inflammation and that modulate other pathophysiologic processes in the lung. The time course and mechanisms of action that contribute to glucocorticoid effects on pulmonary function are also discussed.

Inhibition of human leukocyte metabolism and random mobility by local anaesthesia

Hexose-monophosphate shunt (HMS) activity, myelo-peroxidase-(MPO)-mediated iodination and random mobility in human polymorphonuclear leukocytes (PMNs) were studied in the presence of lignocaine. Incubating the PMNs with 0.1% lignocaine during phagocytosis inhibited the 14CO2 produced from glucose-1-14-C via the HMS shunt by 33%. On increasing the concentration of lignocaine, a dose-dependent inhibition was noted. The MPO-mediated iodination was inhibited by 73% in the presence of 0.1% lignocaine, and complete inhibition took place when the concentration was increased to 0.5%. The random mobility of leukocytes was studied by an opto-electronic technique. In the presence of 0.5% lignocaine, all leukocytes examined were completely immobilized; in the presence of 0.1% lignocaine immobilization took place within 45-65 min.

Pseudomonas aeruginosa clearance in mice: comparison of tissue, strain, and corticosteroid effects

We used a murine model to determine whether chronic corticosteroid therapy has uniform effects on bacterial clearance processes in different tissues. After a 2-week regimen of oral prednisolone, Swiss Webster mice were challenged with Pseudomonas aeruginosa strain PAO1 or virulent derivatives of PAO1 (IP-8 and IT-10). Chronic corticosteroid therapy delayed the clearance of strain PAO1 from the peritoneal cavity. However, steroid treatment did not reduce the neutrophil influx, did not reduce the in vivo phagocytic capacity of neutrophils, and did not alter bactericidal activity of peritoneal exudate cells in vitro. Virulent isolates (IP-8 and IT-10) replicated in the peritoneal cavity in steroid-treated mice even though the neutrophil influx was similar to control mice. In contrast to the abnormal peritoneal clearance, all strains were rapidly cleared from the lungs of control and steroid-treated mice after aerosol challenge. Neutrophil influx into bronchoalveolar spaces was greater in steroid-treated mice than in control mice. All mice (control and steroid treated) survived these challenges, except for some steroid-treated mice infected intraperitoneally with IP-8. These results demonstrate that chronic steroid therapy alters bacterial clearance processes on the peritoneal surfaces to a greater extent than in the lower respiratory tract. The explanation for this altered clearance in the peritoneum is unclear, but cannot be explained by reductions in neutrophil migration to inflammatory stimuli. Therefore, the infectious risk associated with chronic corticosteroid therapy appears to depend on both the tissue and the virulence of the bacterial strain and may reflect alterations in clearance processes other than neutrophil migration.